A mitochondrial import receptor for the ADP/ATP carrier

We have identified a mitochondrial outer membrane protein of 72 kd
(MOM72) that exhibits the properties of an import receptor for the
ADP/ATP carrier (AAC), the most abundant mitochondrial protein.
Monospecific antibodies and Fab fragments against MOM72 selectively
inhibit import of AAC at the level of specific binding to the
mitochondria. AAC bound to the mitochondrial surface is
coprecipitated with antibodies against MOM72 after lysis of
mitochondria with detergent. MOM72 thus has a complementary
function to that of MOM19, which acts as an import receptor for the
majority of mitochondrial proteins studied so far but not for the
AAC. The import pathway of the precursor of MOM72 appears to
involve MOM19 as receptor.